C#

List<string> documents = new List<string>();

private async void btnConvert_Click(object sender, EventArgs e)
{
    using (var client = new HttpClient(new HttpClientHandler() { UseDefaultCredentials = true }))
    {
        client.BaseAddress = new Uri(BaseApiUrl);
        //client.DefaultRequestHeaders.Add("Accept", "application/json");

        // Add an Accept header for JSON format.
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, BaseApiUrl + ApiUrl);

        foreach (string s in docPaths)
        {
            byte[] bte;
            bte = File.ReadAllBytes(docPath);

            string data = JsonConvert.SerializeObject(Convert.ToBase64String(bte));
            documents.Add(data);
        }

        using (var formData = new MultipartFormDataContent())
        {
            foreach (string s in documents)
            {
                //add content to form data
                formData.Add(new StringContent(s, Encoding.UTF8, "application/json"));
            }

            // List of Http Reponse Messages
            var conversions = documents.Select(doc => client.PostAsync(BaseApiUrl + ApiUrl, formData)).ToList();

            //Wait for all the requests to finish
            await Task.WhenAll(conversions);

            //Get the responses
            var responses = conversions.Select
                (
                    task => task.Result
                );

            foreach (var r in responses)
            {
                // Extract the message body
                var s = await r.Content.ReadAsStringAsync();
                SimpleResponse res = JsonConvert.DeserializeObject<SimpleResponse>(s);

                if (res.Success)
                {
                    byte[] pdf = Convert.FromBase64String(res.Result.ToString());

                    // Save the PDF here
                }
                else
                {
                   // Log issue
                }
            }
        }
    }

[HttpPost]
public async Task<List<SimpleResponse>> Post([FromBody]string request)
{
    var response = new List<SimpleResponse>();
    AIMSConverter convert = new AIMSConverter();

    var provider = new MultipartMemoryStreamProvider();
    await Request.Content.ReadAsMultipartAsync(provider);
    foreach (var requestContents in provider.Contents)
    {
        try
        {
            //var result = convert.CovertDocToPDF(requestContents, WebConfigurationManager.AppSettings["tempDocPath"], WebConfigurationManager.AppSettings["tempPdfPath"]);

            //response.Add(new SimpleResponse() { Result = result, Success = true });
        }
        catch (Exception ex)
        {
            response.Add(new SimpleResponse() { Success = false, Exception = ex, Errors = new List<string>() { string.Format("{0}, {1}", ex.Message, ex.InnerException?.Message ?? "") } });
        }
    }

    return response;
}

public class SimpleResponse
{
    public object Result { get; set; }
    public bool Success { get; set; }
    public Exception Exception { get; set; }
    public List<string> Errors { get; set; }
}

I am creating a data structure project. My task is to use a 4D linked list and display Linked List in Windows form.
How can I display my linked list data in Winform and How can I use Cut Copy paste functions? 

public static class ExtensionMethods
{
   public static void DoubleBuffered(this DataGridView dgv, bool setting)
   {
      Type dgvType = dgv.GetType();
      PropertyInfo pi = dgvType.GetProperty("DoubleBuffered", BindingFlags.Instance | BindingFlags.NonPublic);
      pi.SetValue(dgv, setting, null);
   }
}

this.dataGridView1.DoubleBuffered(true);

using System.Reflection;

this.dataGridView1.DoubleBuffered(true);

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace AccountsTree
{
    public partial class Form1 : Form
    {
        clsAccounts cls = new clsAccounts();
        public Form1()
        {
            InitializeComponent();
            
        }
      
        public void filltree()
        {
            treeView1.Nodes.Clear();
            DataTable dt = new DataTable();
            dt = cls.getAccounts();
            treeView1.Nodes.Add("0", "Accounts");

                foreach (DataRow dr in dt.Rows)
                {

                    TreeNode [] node = treeView1.Nodes.Find(dr["MainAccount"].ToString(), true);
                 
                   
                  if (node != null)
                    {


                        node[0].Nodes.Add(dr["AccountCode"].ToString(), dr["AccountCode"].ToString() + dr["Name"].ToString());
                      
                      
                        
                    }
                    

                  
            }
          
                 }

        private void button4_Click(object sender, EventArgs e)
        {
            filltree();
        }
    }
}

USE [master]
GO
/****** Object:  Database [tree]    Script Date: 12/31/2020 19:01:01 ******/
CREATE DATABASE [tree] ON  PRIMARY 
( NAME = N'tree', FILENAME = N'E:\MyProjects\AccountsTree\tree.mdf' , SIZE = 3072KB , MAXSIZE = UNLIMITED, FILEGROWTH = 1024KB )
 LOG ON 
( NAME = N'tree_log', FILENAME = N'E:\MyProjects\AccountsTree\tree_log.ldf' , SIZE = 1024KB , MAXSIZE = 2048GB , FILEGROWTH = 10%)
GO
ALTER DATABASE [tree] SET COMPATIBILITY_LEVEL = 100
GO
IF (1 = FULLTEXTSERVICEPROPERTY('IsFullTextInstalled'))
begin
EXEC [tree].[dbo].[sp_fulltext_database] @action = 'enable'
end
GO
ALTER DATABASE [tree] SET ANSI_NULL_DEFAULT OFF
GO
ALTER DATABASE [tree] SET ANSI_NULLS OFF
GO
ALTER DATABASE [tree] SET ANSI_PADDING OFF
GO
ALTER DATABASE [tree] SET ANSI_WARNINGS OFF
GO
ALTER DATABASE [tree] SET ARITHABORT OFF
GO
ALTER DATABASE [tree] SET AUTO_CLOSE ON
GO
ALTER DATABASE [tree] SET AUTO_CREATE_STATISTICS ON
GO
ALTER DATABASE [tree] SET AUTO_SHRINK OFF
GO
ALTER DATABASE [tree] SET AUTO_UPDATE_STATISTICS ON
GO
ALTER DATABASE [tree] SET CURSOR_CLOSE_ON_COMMIT OFF
GO
ALTER DATABASE [tree] SET CURSOR_DEFAULT  GLOBAL
GO
ALTER DATABASE [tree] SET CONCAT_NULL_YIELDS_NULL OFF
GO
ALTER DATABASE [tree] SET NUMERIC_ROUNDABORT OFF
GO
ALTER DATABASE [tree] SET QUOTED_IDENTIFIER OFF
GO
ALTER DATABASE [tree] SET RECURSIVE_TRIGGERS OFF
GO
ALTER DATABASE [tree] SET  DISABLE_BROKER
GO
ALTER DATABASE [tree] SET AUTO_UPDATE_STATISTICS_ASYNC OFF
GO
ALTER DATABASE [tree] SET DATE_CORRELATION_OPTIMIZATION OFF
GO
ALTER DATABASE [tree] SET TRUSTWORTHY OFF
GO
ALTER DATABASE [tree] SET ALLOW_SNAPSHOT_ISOLATION OFF
GO
ALTER DATABASE [tree] SET PARAMETERIZATION SIMPLE
GO
ALTER DATABASE [tree] SET READ_COMMITTED_SNAPSHOT OFF
GO
ALTER DATABASE [tree] SET HONOR_BROKER_PRIORITY OFF
GO
ALTER DATABASE [tree] SET  READ_WRITE
GO
ALTER DATABASE [tree] SET RECOVERY SIMPLE
GO
ALTER DATABASE [tree] SET  MULTI_USER
GO
ALTER DATABASE [tree] SET PAGE_VERIFY CHECKSUM
GO
ALTER DATABASE [tree] SET DB_CHAINING OFF
GO
USE [tree]
GO
/****** Object:  Table [dbo].[Accounts]    Script Date: 12/31/2020 19:01:03 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
SET ANSI_PADDING ON
GO
CREATE TABLE [dbo].[Accounts](
	[AccountID] [int] IDENTITY(1,1) NOT NULL,
	[AccountCode] [varchar](50) NOT NULL,
	[MainAccount] [varchar](50) NOT NULL,
	[Name] [varchar](100) NULL,
	[AccountType] [tinyint] NOT NULL,
	[Debit] [real] NULL,
	[Credit] [real] NULL,
 CONSTRAINT [PK_Accounts] PRIMARY KEY CLUSTERED 
(
	[AccountID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY],
 CONSTRAINT [IX_Accounts] UNIQUE NONCLUSTERED 
(
	[AccountCode] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
SET ANSI_PADDING OFF
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountID'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=1800 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'كود الحساب' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountCode'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'الحساب الرئيسى' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'MainAccount'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=2655 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'اسم الحساب' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Name'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'2 حساب رئيسى1   : حساب فرعى' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'AccountType'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'مدين' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Debit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnHidden', @value=N'False' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnOrder', @value=0 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_ColumnWidth', @value=-1 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Description', @value=N'دائن' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DisplayControl', @value=N'109' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Format', @value=N'' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_IMEMode', @value=N'0' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts', @level2type=N'COLUMN',@level2name=N'Credit'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_DefaultView', @value=0x02 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Filter', @value=NULL , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_OrderBy', @value=N'Accounts.AccountName' , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_Orientation', @value=NULL , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
EXEC sys.sp_addextendedproperty @name=N'MS_TableMaxRecords', @value=10000 , @level0type=N'SCHEMA',@level0name=N'dbo', @level1type=N'TABLE',@level1name=N'Accounts'
GO
/****** Object:  StoredProcedure [dbo].[selectAc]    Script Date: 12/31/2020 19:01:12 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
Create proc [dbo].[selectAc]
as
select * 
from
Accounts
GO
/****** Object:  Default [DF_Accounts_MainAccount]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_MainAccount]  DEFAULT ('') FOR [MainAccount]
GO
/****** Object:  Default [DF_Accounts_AccountType]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_AccountType]  DEFAULT ((2)) FOR [AccountType]
GO
/****** Object:  Default [DF_Accounts_Debit]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_Debit]  DEFAULT ((0)) FOR [Debit]
GO
/****** Object:  Default [DF_Accounts_Credit]    Script Date: 12/31/2020 19:01:03 ******/
ALTER TABLE [dbo].[Accounts] ADD  CONSTRAINT [DF_Accounts_Credit]  DEFAULT ((0)) FOR [Credit]
GO

Index was outside the bounds of the array.